Steam-boiler economizer



March 5, 1929. w. A. JONES 1,704,132

swam some: acouomzmn Filed Ap ril- 10, 1925 Z I I 4IZENTOR.

M By %4V/a1i ATTORNEYS.

Patented Mar. 5, .1929.

UNITED STATES PATENT OFFICE.

\VILLIAM A. JONES, OF WEST NEW BRIGHTON, NEW YORK, ASSIGNOR TO THE BAB-OOCK & WILCOX COMPANY, OF BAYONNE, NEW JERSEY, A CORPORATION OF NEWJERSEY.

STEAM-BOILER ECONOMIZER.

Application filed April 10, 1925. Serial No. 22,032.

understood from the following description and the annexed drawing, inwhich the fi ure represents a sectional elevation of one orm of Stirlingboiler with an economizer embodying my invention connected thereto.

In the illustrative embodiment, the boiler has three upper steam andwater drums 10, 11 and 12 and a lower water drum 13 connected by banksof tubes 14, 15 and 16 with a steam ofit'take at 17 leading to thesuperheater 18, the hot gases being supplied from a furnace 19 and beingdirected by the bafiles shown along the tubes in the severalbanks to agas outlet at the lower part of the bank 16.

In the same setting is an economizer having an upper water drum 20 andalso a water drum 21 connected by a bank of tubes which are arrangedinrows 22, 23, 24, 25, 26, 27, 28, 29 and 30, these tubes being arrangedin a manner to be described more in detail hereafter. The gases from theboiler are directed to the upper part of the bank of tubes connectingthe drums 20 and 21 by a bafiie 31 and are directed thence back andforth across this .bank of tubes by baflles 32 and 33 to the gas outlet34. In the illustrative embodiment, the feed water inlet 35 supplies theboiler feed water to the drum 21 and the water, after being heated inthe economizer, passes through a pipe or pipes 36 to the water space ofthe drum 12.

In economi'zers, such as that illustrated in and 21 which would notarise if these tubes were part of the general boiler circulation, wherethe temperature of the water is substantially the same throughout thesystem and where changes in the rate of supply of feed water to theboiler circulation doesnot materially afiect the temperature of theboiler water and doesnot, therefore, cause contraction and expansion ofthe boiler tubes. Hence, 1n such economizers, it is desirable to arrangethe economizer tubes so that they can contract and eirpand withoutputting undue strain on the o nts between the tubes and the drums. Toth1s end, I provide an arrangement by WlllCh each tube will have enoughcurvature at at least one end to prevent an undue amount of strainthrough differences in expansions of the tubes in the several rows. ItWlll be noted that each tube has a straight part for the greater portionof its length, the ends belng bent'so as to enter each drum radlally.These straight parts are parallel and make an angle with the lineconnecting the centers of the drums 20 and 21, this angle, of

course, being the same for all the straight parts of the tubes.

Moreover, I preferably arrange the tubes so that in eachrow in a planeat right angles to the axes of the drums, which is the plane seen in thedrawing, a tube on one side of the center. line of the bank of which therow is a part, will be a duplicate of a tube in the row and on the otherside of said center line, but turned end for end. By center line of thebank, I refer to the center line of the parallel straight portions ofthe tubes forming the bank. This makes it unnecessary to carry as manyspare tubes for replacement as would be required were the tubes bent toa different form in every row. Furthermore, by this arrangement, whilethe majority of the tubes have a very large bend at one end and arelatively small bend at the other, all of the tubes have suflicientbends. either at one end or at both ends, so that the tube will respondto contraction or expansion without putting undue strain on the jointsbetween the tubes and the'drums. Moreover, it will be noted that tube22, for instance, is a duplicate of tube 30 but turned end for end.Similarly tube 23 is a duplicate of tube 29, tube 24 is a duplicate oftube 28 and tube 25 is a duplicate of tube 27. Thus the construction isgreatly simplified while, at the same time, the advantages above notedas to flexibility under strain is obtained.

While the drawing shows a tube arrangement in which the tubes in a givenrow are all in the same plane, it will be understood that the tubes in'such a row may be slightly ofiset from the common plane to produce astaggered effect, and that in the foregoing description and the appendedclaims I have used the word row to include not only an arrangement inwhich the tubes in such row are in exactly the same plane, but also anarrangement in which the tubes may be offset alternately from suchcommon plane.

It will be understood that the arrangement which I have shown is merelyillustrative and that the embodiment of my invention may be widelyvaried.

-I claim:

1. In a fluid heater, a pair of drums of substantially equal diameterspaced apart, a bank of tubes connecting the drums and having their endsentering the drums normal to the surfaces thereof with their endsexpanded into said drums, each tube of the bank having the greaterportion thereof straight and parallel to the straight portions of theother tubes of the bank and extending atan angle to the line connectingthe centers of said drums, each tube being curved to a substantialamount at at least one end, and each tube on one side of the center lineof the bank be ing a duplicate as to shape and length of a tube on theother side of said center line.

2. A steam boiler economizer having .an upper and a lower water drum ofsubstantially equal diameter, a bank of tubes connecting said drums,said tubes being arranged in rows extending atright-angles to the axesof the drums, each tube in each such row having the greater portionthereof straightand parallel to the straight portions of the other tubesof the row, the ends of each tube entering the drums normal to thesurface thereof, the majority of said tubes having a curve at one end ofa substantially greater amount than at the other end, the tubes at oneside of the center line of the row having the large curves entering onedrum and the tubes at the other side of said center line having thelarge curves entering the other drum, each tube at one side of saidcenter line being like a tube at the other side of the center line as tolength and shape, a

a water inlet in one of said drums, and a water outlet in the other ofsaid drums and leading to the boiler. I

3. A fluid heater having an upper and a lower drum of substantiallyequal diameter, a bank of tubes connecting said drums, said tubes beingarranged in rows extending at right-angles to the axes of the drums,each tube in each such row having the greater portion thereof straightand parallel to the straight portions of the other tubes of the upperand a lower Water drum of substantially equal diameter, a bank of tubesconnectmg said drums, said tubes being arranged in rows extending atright-an les to the axes of the drums, each tube in eac such row 7having the greater portion thereof straight and parallel to the straightportions of the other tubes of the row and extending at an angle to theline connecting the centers v of said drums, the ends of each tubeentering the drums normal to the surface thereof and one end at leastbeing curved to a substantial amount, each tube in each such row on oneside of the center line of the bank being a du plicate as to shape andlength of a tube onthe other side of said center line of the bank butturned end for end, a feed water inlet to to the line connecting thecenters of said drums, the ends of each tube entering the drums normalto the surface thereof and one end at least being curved to asubstantial amount, each tube in each such row on one side of the centerline of the bank being a duplicate as to shape and length of a tube onthe other. side of said center line of the bank but turned end for end,a feed water inlet to said lower drum, an outlet from said upper drum,and means causing heated gases to flow downwardly over all of saidtubes.

WILLIAM' A. JONES.

